Disconnecting switch with compensated electrodynamic forces



- y 3, 1 c. BRESSON DISCONNEQTING SWITCH WITH COMPENSATED ELECTRODYNAIICFORCES Filed March 27, 1931 imfe/zl'or C/zarleaZresa OIL Patented May 81934 a I UNITED STATES PATENT OFFICE DISCONNECTING SWITCH WITH COIVIPEN-SATED ELECTRODYNAMIC FORCES Charles Bresson, Villeurbanne, France,assignor to Ateliers de Constructions Electriques de Belle, Paris,France Application March 27, 1931, Serial No. 525,846 In Germany March28, 1930 2 Claims. (Cl. 200-87) The disconnecting switches of electriclines are By suitably selecting the dimensions of the generally formedwith a knife blade forming a loop a, b, c, d, the loop a b c' it may bedispensed loop with the current leads. When a short circuit with andneverthelessa resultant F directed downoccurs a field is generatedwithin the loop and wards obtained. This is shown in Fig. 3, wherein 5the forces thus generated open the disconnecting the blade is pivoted atA and opens the line 60 switch. at X.

A disconnecting switch of this character can- In the constructionillustrated in Fig. 2 the curnot be utilized on lines where shortcircuit current is lead in by way of a terminal P fromwhich rents areheavy in view of the fact that the knife extend two shaped conductors Gat the free end blade would open at each short circuit. of which isfixed a contact having jaws M. The 55 The present invention avoids thisdisadvanparts G thus form the loop designated by a b c d tage. It hasfor its object a disconnecting switch in Fig. 1. One of the arms G maybe dispensed characterized in this that the current leads form with. atleast at one of the ends of the knife blade 3. Having now particularlydescribed and ascerloop which gives to the electrodynamic forcesacttained the nature of my said invention and in 79 ing on the knifeblade a direction such that the what manner the same is to be performed,I deopening of the knife under the action of short clare that what Iclaim is: circuit currents may be avoided. 1. A disconnecting switch forelectric lines,

Figs. 1 and 2 show respectively a schematic arcomprising a movable knifeblade adapted to conrangement and a part view of a disconnecting nectthe two extremities of a part of an electric 75 switch in accordancewith the invention and Figline, knife blade supports carrying the linecurure 3 is a diagrammatic representation of a modirent and forming withthe blade a first loop, the fied form of the invention wherein one sideloop is blade moving away from the center of this loop dispensed with.The knife blade is denoted by to open the line, and aloop formed by oneextremi- C and the two loops formed by the conductors by ty of the bladesupport with the corresponding 80 a, b, c, d, and by a, b, c, d. Thedisconnecting end of the blade, and above said blade, the secswitchopens by moving the knife blade upwards. ond loop being opposed to thefirst.

The apparatus thus forms three loops, a large 2. In a disconnectingswitch, a displaceable loop D d, d, E, as also two small loops a b c dand knife blade forming several loops with the exa b c 11. These threeloops generate electrotremities of an .electric line which said bladecondynamic forces F1, F2, F3, the first of which is dinects together,and a forked support at the openrected upwards while the two others tendto oping end of the blade and constituted by the expose the opening ofthe knife blade. The dimentremities of the line to be opened, saidforked sions a d, d d and d a. are so selected that the supportconstituting a loop above the blade and 35 resultant of the three forcesF is directed downin planes parallel to the plane of said blade andwards and consequently opposes the opening of at each side thereof. theknife blade. I CHARLES BRESSON.

